try this one

Gem

FUDGE CAKE

7 oz Self Raising Flour
8 oz Caster sugar
½ tsp salt
1 oz cocoa powder,
4 oz margarine
2 medium eggs
5 tbsp evaporated milk
5 tbsp water few drops

Mix flour, sugar, salt and cocoa.  Rub in margarine. Beat eggs with milk. Stir egg mixture, essence and liquids into the dry ingredients and beat well. Place mixture in prepared tins and bake for about 30-35 minutes.
Gas Mark 4. Grease 2 x 20.5 cm (8 inch) tins, not loose-bottomed as the mixture would run out.

2½ oz margarine
1 tbsp cocoa powder
9 oz sieved icing sugar
3 tbsp hot milk
1 tsp vanilla essence
Melt margarine, blending in cocoa, then stir in icing sugar, milk and essence. Beat until smooth and thick.